Sylvain Jean Mairet (1805-1890) Raised by his uncle F.I. Favre-Bulle, a great watchmaker, he became one of the best watchmakers in Le Locle. Between 1831 and 1834 he lived in London, making watches, often to his own design, and mostly for Vulliamy. He became friendly with J. F. Cole. He invented stem winding for watches with two-train movements. In 1862 he was Swiss agent to the London Universal Exhibition, writing the official report. At the 1867 Paris Exhibition he received a gold medal for ?his ability and the beneficial influence which he had exerted on the progress of watchmaking in the Canton of Neuchâtel". René Antoine Ferchault de Réaumur (1683 - 1757) Born in La Rochelle, René Antoine Ferchault de Réaumur pursued his studies first in his native city, and then in Poitiers and in Bourges. After studying law, he turned to mathematics, which he studied in Paris beginning in 1703. The publi-cation of his ?Memoirs in Geometry? brought him to the attention of the Académie des sciences. Réaumur joined the Académie when he was only twenty-five and became director of the publication "Description des divers arts et métiers". Réaumur studied many things, including the ductility of metals, the resistance of cables, and the magnetism of iron. His research into iron alloys is particularly important and was presented in "l'Art de convertir le fer forgé en acier et l'art d'adoucir le fer fondu" in 1722. This research led to the introduction of steel in France. Réaumur studied the composition of metals under a microscope, thus founding the study of metallography. In 1730, he constructed the first alcohol thermometer, for which he designed a scale from 0 to 80 and whose indications allow for comparison. Réaumur also made important contributions to the natural sciences, being particularly interested in the study of invertebrates. He began a 12-volume work, "Mémoires pour servir à l'histoire des insectes" (1734-1742), which